Parents may set up individual accounts with individualized parental controls for each of their children to enable their children to authenticate to a computing system and be protected and restricted from inappropriate activities and content. Unfortunately, children often circumvent traditional parental-control mechanisms by authenticating as a different user (e.g., a sibling, a parent, a friend, etc.) or otherwise accessing a different user's account without permission (e.g., by accessing another person's account if the person fails to log out). When a child is accessing a computing system under a different user's account, the child may not be bound by the same policies and rules that restrict the child under his or her own account. In such situations, a child may be exposed to inappropriate content and/or may participate in activities that are restricted within the child's own account. What is needed, therefore, is a more efficient and effective mechanism for validating authentication of children and other users who may attempt to circumvent traditional authentication and control mechanisms.